See
here for better historical data.
The last rounds that were won by XP planets were 74, 67 (a fluke: def XP) and 59. XP rounds are few and far between. You dislike them, but some people really enjoy them, and for that reason alone I think it's fine to have one every now and again. Honestly, a bit more often than we currently do, in my opinion.
With the current implementation of XP, the ship stats are what determine whether a round becomes an XP round or not. Since those are under 'our' (Jintao's) control, I don't see the problem.